Currently it is known to deposit the spacer frame or the spacer profile on a glass pane and then mate the assembly to a second glass pane and seal it along the entire outer peripheral region so as to constitute the so-called insulating glazing unit or double glazing unit. Such operation can also be a multiple one in order to obtain the insulating glazing unit constituted by three glass panes and two spacer frames or profiles, as well as n glass panes and n−1 spacer frames or profiles. The operation can also relate to glass panes that have different dimensions despite belonging to the same insulating glazing unit, so as to obtain an offset between their edges, which is necessary for mating with a particular type of door or window, i.e., the one that constitutes the so-called continuous glazing or the so-called structural glazing. Frequently, the spacer frame or, more correctly, the profile that constitutes it, has a hollow rectangular transverse cross-section that is bevelled toward the outside of the double-glazing unit to accommodate a larger quantity of sealant, but sometimes spacer frames or, more correctly, spacer profiles are used which have complex transverse cross-sections. In this situation, the perimetric seal, in the background art, can only be performed manually.
The present invention relates indeed to these types of insulating glazing unit with spacer frames constituted by profiles having a complex cross-section.
In order to better define and understand the configuration of an insulating glazing unit in the combination of its components, i.e., the glass pane 2 and the spacer profile or frame 3, and as regards the final product, i.e., the insulating glazing unit 1, some concepts related to the intermediate components are summarized hereafter, with reference to FIGS. 1A to 1G and with the assumption that the subsequent use of the insulating glazing unit, i.e., as a component of the door or window, is known.
In order to provide a more efficient and intelligible description, it will be started hereinafter from the description of the final product and then to the product broken up into its components.
The insulating glazing unit 1 is constituted by the composition of two or more glass panes 2, which are separated by one or more spacer frames 3, which are generally hollow and finely perforated on the face that is directed inward. The spacer frames contain hygroscopic material 4 in their hollow part and are provided on the lateral faces with a butyl, first sealant 5, which constitutes the so-called first seal. The chamber (or chambers) delimited by the glass panes 2 and by the spacer frame (spacer frames) 3 is able to contain air or gas or mixtures of gases that give the double-glazing unit particular properties, for example thermally insulating and/or soundproofing properties.
Widespread use is made of a spacer profile 3 which has a substantially rectangular cross-section and is fabricated of expanded synthetic material (by way of non-limiting example: silicone and EPDM) which incorporates the hygroscopic material in its mass. Spacer frames constituted by profiles having a complex cross-section are also used and necessary.
The joint between the glass panes 2 and the spacer frame (frames) 3 is achieved by means of two levels of sealing: the first one with first sealant 5 is intended to provide tightness and initial bonding between such components and is applied to the lateral surfaces of the frame and the portions of the adjacent glass panes, already mentioned earlier; the second one with second sealant 6 is intended to provide final cohesion among the components and mechanical strength of the joint among them and is applied at the compartment constituted by the outer surface of the spacer frame 3 and by the faces of the glass panes 2 up to their edge (see FIGS. 1A to 1G). In the case of a spacer profile 3 made of expanded synthetic material, the first level of sealing is replaced with, or integrated by, an adhesive material, for example an acrylic one, which is already spread onto the lateral faces of such spacer profile and is covered by a removable protective film. This type of spacer profile will not be referenced further in the continuation of the description, since it is a very different type with respect to the one to which the present patent application relates.
The glass panes 2 used in the composition of the insulating glazing unit 1 can have different configurations depending on the use of such unit: for example, the outer pane (outer with respect to the building) can be normal or reflective (in order to limit the heat input during summer months) or laminated/armored (for intrusion prevention/vandalism prevention functions) or laminated/tempered (for safety functions) or combined (for example reflective and laminated, to obtain a combination of properties); the inner pane (inner with respect to the building) can be normal or of the low-emissivity type (in order to limit the dispersion of heat during winter months) or laminated/tempered (for safety functions) or combined (for example of the low-emissivity type and laminated to obtain a combination of properties). In particular, the outer glass pane 2M can be larger than the inner one (ones) 2m along the entire extension of the perimeter or only on one side or only on some sides (see FIGS. 1E and 1F). In particular, moreover, the cross-section of the profile that constitutes the frame can have a complex shape, for example a shape with fins toward the outside, such as the one with which the present invention deals.
The above summary makes it already evident that a manufacturing line for obtaining the insulating glazing unit product 1 requires many processes in sequence and, in particular, comprises the second sealing process, with which the present application deals in detail in the embodiment in which the spacer profile 3 has such a shape as to entail difficulties in such sealing, so much that before the present invention it was performed only manually.
Prior art documents belonging to the same field and describing automatic machines and automatic/manual methods for perimetric sealing by performing second sealing regard processes only directed to the step in which the sealing product is distributed automatically proximate to the spacer profile 3 having only a simple shape. Here, the profile 3 is mechanically joined to the glass panes 2 and alignment with the edges of the glass panes 2 or with the edge of the smaller glass pane 2m is made to provide mechanical bond between the spacer frame and the glass sheets and strength to the joint. This further allows to constitute a further tightness—providing barrier sealant 6 (the main barrier being constituted by the first butyl sealant 5) against moisture, which must not penetrate within the insulating glazing unit 1, and against the filling gas, which must not escape toward the outside of the insulating glazing unit 1. The most significant documents are believed to be:                EP0391884 B2 and corresponding U.S. Pat. No. 5,136,974, in the name of Lisec Peter, relating to a specific device for applying the sealant to the perimetric edge of the insulating glazing unit, and describing the correlation between the geometry of the perimetric joint, i.e., the distance between the glass panes and the difference in level between the outer face of the spacer frame and the edges of the glass panes, or the edge of the smaller glass pane, the relative speed between the extrusion head and the insulating glazing panel, the flow-rate of the dosage pump, in order to obtain complete filling of the perimetric joint without causing overflow of the sealant;        EP0471247 A1, in the name of Lenhardt Karl, relating to a specific device for applying sealant to the perimetric edge of the insulating glazing unit, either automatically, and therefore describing the components for pumping, dosage and controlled extrusion against the perimetric edge of the insulating glazing unit during the relative motion between the insulating glazing unit and the extrusion head, or manually, and therefore using only the components for the pumping and mixing of the automatic device but resorting to a manual extrusion gun for application to the insulating glazing unit, the dosage being entrusted to the manual skills and ability of the operator; this occurs when the profile of the spacer frame has a complex cross-section and therefore the automatic and progressive gauging of the cavity in order to adjust the dosage of the sealant is not possible.        
Here a manual extrusion gun is used, which moreover is already background art albeit with other pumping criteria. Such process is the only one that allows, by resorting to equally known contoured nozzles, second manual sealing in the situation of spacer profiles that have a complex shape, particularly, by way of non-exclusive example, profiles with fins of the Schüco type.
Manual sealing operations, however are known to be difficult and to require highly skilled operators. Moreover, they do not provide any guarantee that the various sealings are made with a same efficiency and optimum quantities of sealing materials.